In pneumatic tires for heavy load vehicles, in order to preserve the traction performance of the tire, the tread surface of the tread portion situated between both tread ends is conventionally formed with lug grooves extending in the tire width direction such that at least one end of the lug groove opens in the tread end.
Pneumatic tires for heavy load vehicles are known, wherein the traction performance is preserved by forming lug grooves in the tread surface so that one end of the lug groove opens in the tread end on one side in the tire width direction and the other end terminates at a location between the both tread ends. For such tires, there has been proposed to improve the anti-cut/separation property of the tire by forming sipes that are deeper than the lug groove and thereby achieving a communication, in the tire width direction, of a lug groove that opens at the tread end on one side in the tire width direction, with a lug groove that opens at the tread end on the other side in the tire width direction (refer, for example, to Patent Document 1). Here, the term “cut/separation” refers to separation of the tread rubber that occurs along the outer peripheral surface of the belt when the widthwise center region of the tread portion (hereinafter referred to as “the tread center region”) is subjected to deep injury that reaches as far as the belt.
Moreover, in the above-mentioned conventional pneumatic tires for heavy load vehicles wherein the lug groove on one side in the tire width direction is communicated by a sipe with the lug groove on the other side in the tire width direction, it is possible to suppress the shearing deformation of the tread rubber situated on the stepping-in side during the loaded rolling of the tire and thereby improve the anti-cut/separation property of the tire, by arranging sipes that are deeper than the lug groove.